.\"	$OpenBSD: table.5,v 1.14 2024/05/02 18:14:33 op Exp $
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.\" Copyright (c) 2013 Eric Faurot <eric@openbsd.org>
.\" Copyright (c) 2013 Gilles Chehade <gilles@poolp.org>
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.Dd $Mdocdate: May 2 2024 $
.Dt TABLE 5
.Os
.Sh NAME
.Nm table
.Nd format description for smtpd tables
.Sh DESCRIPTION
This manual page documents the file format for the various tables used in the
.Xr smtpd 8
mail daemon.
.Pp
The format described here applies to tables as defined in
.Xr smtpd.conf 5 .
.Sh TABLE TYPES
There are two types of tables: lists and mappings.
A list consists of a series of values,
while a mapping consists of a series of keys and their associated values.
The following illustrates how to declare them as static tables:
.Bd -literal -offset indent
table mylist { value1, value2, value3 }
table mymapping { key1 = value1, key2 = value2, key3 = value3 }
.Ed
.Pp
When using a
.Ql file
table, a list will be written with each value on a line by itself.
.Bd -literal -offset indent
value1
value2
value3
.Ed
.Pp
A mapping will be written with each key and value on a line,
whitespace and an optional colon separating both columns:
.Bd -literal -offset indent
key1:	value1
key2	value2
key3	value3
.Ed
.Pp
Blank lines, leading and trailing spaces and tabs are ignored.
Lines whose first non-space character is a hash mark
.Pq Sq #
are comments and are ignored.
To force the parsing of a file table as a list rather than a mapping, use
this special comment:
.Pp
.Dl # @list
.Pp
A file table can be converted to a Berkeley database using the
.Xr makemap 8
utility with no syntax change.
.Pp
Tables using a
.Ql file
or Berkeley DB backend will be referenced as follows:
.Bd -unfilled -offset indent
.Ic table Ar name Cm file : Ns Pa /path/to/file
.Ic table Ar name Cm db : Ns Pa /path/to/file.db
.Ed
.Ss Aliasing tables
Aliasing tables are mappings that associate a recipient to one or many
destinations.
They can be used in two contexts: primary domain aliases and virtual domain
mapping.
.Bd -unfilled -offset indent
.Ic action Ar name method Cm alias Pf < table Ns >
.Ic action Ar name method Cm virtual Pf < table Ns >
.Ed
.Pp
In a primary domain context, the key is the user part of the recipient address,
whilst the value is one or many recipients as described in
.Xr aliases 5 :
.Bd -literal -offset indent
user1	otheruser
user2	otheruser1,otheruser2
user3	otheruser@example.com
.Ed
.Pp
In a virtual domain context, the key is either a user part, a full email
address or a catch-all, following selection rules described in
.Xr smtpd.conf 5 ,
and the value is one or many recipients as described in
.Xr aliases 5 :
.Bd -literal -offset indent
user1			otheruser
user2@example.org	otheruser1,otheruser2
@example.org		otheruser@example.com
@			catchall@example.com
.Ed
.Pp
The following directive shares the same table format,
but with a different meaning.
Here, the user is allowed to send mail from the listed addresses:
.Bd -unfilled -offset indent
.Ic listen on Ar interface Cm auth Oo Ar ... Oc Cm senders Pf < Ar table Ns >
.Ed
.Ss Domain tables
Domain tables are simple lists of domains or hosts.
.Bd -unfilled -offset indent
.Ic match Cm for domain Pf < table Ns > Cm action Ar name
.Ic match Cm helo Pf < table Ns > Oo Ar ... Oc Cm action Ar name
.Ed
.Pp
In that context, the list of domains will be matched against the recipient
domain or against the HELO name advertised by the sending host,
respectively.
For
.Ql static ,
.Ql file
and
.Xr dbopen 3
backends, a wildcard may be used so the domain table may contain:
.Bd -literal -offset indent
example.org
*.example.org
.Ed
.Ss Credentials tables
Credentials tables are mappings of credentials.
They can be used in two contexts:
.Bd -unfilled -offset indent
.Ic listen on Ar interface Cm tls Oo Ar ... Oc Cm auth Pf < Ar table Ns >
.Ic action Ar name Cm relay host Ar relay-url Cm auth Pf < Ar table Ns >
.Ed
.Pp
In a listener context, the credentials are a mapping of username and encrypted
passwords:
.Bd -literal -offset indent
user1	$2b$10$hIJ4QfMcp.90nJwKqGbKM.MybArjHOTpEtoTV.DgLYAiThuoYmTSe
user2	$2b$10$bwSmUOBGcZGamIfRuXGTvuTo3VLbPG9k5yeKNMBtULBhksV5KdGsK
.Ed
.Pp
The passwords are to be encrypted using the
.Xr smtpctl 8
encrypt subcommand.
.Pp
In a relay context, the credentials are a mapping of labels and
username:password pairs:
.Bd -literal -offset indent
label1	user:password
.Ed
.Pp
The label must be unique and is used as a selector for the proper credentials
when multiple credentials are valid for a single destination.
The password is not encrypted as it must be provided to the remote host.
.Ss Netaddr tables
Netaddr tables are lists of IPv4 and IPv6 network addresses.
They can only be used in the following context:
.Pp
.D1 Ic match Cm from src Pf < Ar table Ns > Cm action Ar name
.Pp
When used as a "from source", the address of a client is compared to the list
of addresses in the table until a match is found.
.Pp
A netaddr table can contain exact addresses or netmasks, and looks as follow:
.Bd -literal -offset indent
192.168.1.1
[::1]
192.168.1.0/24
.Ed
.Pp
IPv6 addresses must be enclosed in square brackets.
.Ss Userinfo tables
Userinfo tables are used in rule context to specify an alternate userbase,
mapping virtual users to local system users by UID, GID and home directory.
.Pp
.D1 Ic action Ar name method Cm userbase Pf < Ar table Ns >
.Pp
A userinfo table looks as follows:
.Bd -literal -offset indent
joe	1000:100:/home/virtual/joe
jack	1000:100:/home/virtual/jack
.Ed
.Pp
In this example, both joe and jack are virtual users mapped to the local
system user with UID 1000 and GID 100, but different home directories.
These directories may contain a
.Xr forward 5
file.
This can be used in conjunction with an alias table
that maps an email address or the domain part to the desired virtual
username.
For example:
.Bd -literal -offset indent
joe@example.org     joe
jack@example.com    jack
.Ed
.Ss Source tables
Source tables are lists of IPv4 and IPv6 addresses.
They can only be used in the following context:
.Pp
.D1 Ic action Ar name Cm relay src Pf < Ar table Ns >
.Pp
Successive queries to the source table will return the elements one by one.
.Pp
A source table looks as follow:
.Bd -literal -offset indent
192.168.1.2
192.168.1.3
[::1]
[::2]
.Ed
.Pp
IPv6 address must be enclosed in square brackets.
.Ss Mailaddr tables
Mailaddr tables are lists of email addresses.
They can be used in the following contexts:
.Bd -unfilled -offset indent
.Ic match Cm mail\-from Pf < Ar table Ns > Cm action Ar name
.Ic match Cm rcpt\-to Pf < Ar table Ns > Cm action Ar name
.Ed
.Pp
A mailaddr entry is used to match an email address against a username,
a domain or a full email address.
A "*" wildcard may be used in part of the domain name.
.Pp
A mailaddr table looks as follow:
.Bd -literal -offset indent
user
@domain
user@domain
user@*.domain
.Ed
.Ss Addrname tables
Addrname tables are used to map IP addresses to hostnames.
They can be used in both listen context and relay context:
.Bd -unfilled -offset indent
.Ic listen on Ar interface Cm hostnames Pf < Ar table Ns >
.Ic action Ar name Cm relay helo\-src Pf < Ar table Ns >
.Ed
.Pp
In listen context, the table is used to look up the server name to advertise
depending on the local address of the socket on which a connection is accepted.
In relay context, the table is used to determine the hostname for the HELO
sequence of the SMTP protocol, depending on the local address used for the
outgoing connection.
.Pp
The format is a mapping from inet4 or inet6 addresses to hostnames:
.Bd -literal -offset indent
[::1]		localhost
127.0.0.1	localhost
88.190.23.165	www.opensmtpd.org
.Ed
.Pp
IPv6 addresses must be enclosed in square brackets.
.Sh SEE ALSO
.Xr smtpd.conf 5 ,
.Xr makemap 8 ,
.Xr smtpd 8
